FINANCIAL INSTRUMENTS: (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Mar. 31, 2015
Fair value of assets and liabilities
Other current assets	$ 35,918	$ 34,975
Fair value measurements on recurring basis | Total
Fair value of assets and liabilities
Other current assets	12,731
Total assets	12,731
Other accrued expenses	52
Total liabilities	52
Fair value measurements on recurring basis | Level 1
Fair value of assets and liabilities
Other current assets	12,731
Total assets	12,731
Fair value measurements on recurring basis | Level 2
Fair value of assets and liabilities
Other accrued expenses	52
Total liabilities	$ 52